Change Tab Title

Trying to get the browser tab to read the title of my page (or the title of the individual post). It used to read this but for some reason it stopped today (I did have to restore to a previous backup from a few days ago, so maybe that was the problem). As of now, the tab doesn’t read the title of my site—it reads the URL of my site, which is just really unattractive. How to fix this?

Thanks!